The present invention relates to a support system for positioning and supporting non-circular linear elements, such as tubing bundles, electrically heated tubing, multi-wire electric cables, and the like. Such elements have a cross-section with a major dimension and a minor dimension. They require support at minimum intervals ranging from six inches to twenty feet.
In many applications, including off-shore platforms and many on-shore refineries, chemical plants, and the like, linear elements like tubes, tubing bundles, and the like, are routed through the facility, sometimes in conduits. The tubes are prone to rubbing against each other or against the wall of the conduit, particularly when the conduit bends or when it is subject to vibration, as may be caused by wind, waves, or seismic events. Abrasion of the tubes or of the conduit by the tubes may lead to corrosion or leaks. The problem is compounded when larger diameter tubing (one-quarter inch diameter and up) is shipped in coils to the job site, thereby taking a permanently curved set, or when plural tubes are surrounded by a common jacket to form a tubing bundle. The problem is further compounded when the tubing package includes tracing or multiple tubes, and the linear element is therefore non-circular in cross-section.
One example of such an application is an offshore production facility in which a subsurface isolation valve is controlled by hydraulic piping extending from above surface along a hollow leg of the facility to the valve. The leg may have a considerable length, often from twenty-five to two hundred feet. A typical example is a generally vertical leg having a length of one hundred fifty feet from an above-surface production platform or deck to a subsurface porch supporting the valve. Tubing bundles containing two or more stainless steel tubes, illustratively having a half-inch diameter, may constitute the hydraulic piping. In such a facility, the weight of the tubing itself requires substantial support. Such facilities are well known. Examples are shown in Arrazola et al., U.S. Pat. No. 8,857,522 and Morrill, U.S. Pat. No. 4,477,205.
Both inside a conduit and outside a conduit, such non-circular linear elements require special care when they must make a turn, in order to avoid kinking or excess bowing of the tubes. In making a turn relative to in any direction other than around the shortest cross-sectional dimension, the linear element must be allowed to twist. Conventional supports limit twisting to reaches between supports.